A number of fats, other ingredients, and processing conditions have been suggested for use in preparing filled biscuit sandwiches. Hydrogenated coconut and palm kernel oils are most used for cream fillings (Manley, D. J. R., Technology of Biscuits, Crackers and Cookies, Ellis Horwood, Ltd., Chichester, 1983, pages 72 to 74). However, these lauric fats exhibit cooling difficulties and have a tendency to supercool. On leaving the plasticizer, the fat is often too fluid to have been well plasticized. As the supercooling is relieved, the mass sets up making extraction from a bulk store difficult unless the general temperature is considerably higher than 20.degree. C. If creams are made from fat that is warm, it is not possible to achieve the same amount of aeration with open type mixers, and the resulting cream is rather soft for most creaming machines (ibid.).
Controlled creamed biscuit cooling and good pressure following topping of the sandwich have been suggested to alleviate the problem (id. at 343 to 344). Either the cream should be warmer at depositing or the biscuit shell should be warmer than the cream. Where cooling is done, this should be minimal to effect a desired firmness of the cream on the hottest day. Cooling air temperatures should be adjusted so that the biscuits are not taken to below the dew point so that condensation does not spoil biscuit shell quality, or adhesion at the biscuit-cream interface. Because of the high cost of operations and plant space for cooling tunnels, many plants do not cool their sandwich cookies and crackers either long enough or low enough (Smith, W. H., Biscuits, Crackers and Cookies, vol. 1, MFI, New York, 1972, pages 332 to 333).
U.S. Pat. No. 4,587,128 to Cummings suggested that a bonding layer be employed to make a snack food product, and that a pressure bearing member in the production equipment press the components into intimate contact with the bonding layer, but this complicates manufacture by adding another component and a pressure bearing member.
Even where desirable processing conditions have been achieved, food products containing hydrogenated lauric fats have fallen into disfavor for other reasons. These fats are high in calories, and tend to have significant levels of lauric, myristic and palmitic acids in their saturated acid complement, and significant levels of trans-unsaturation in their unsaturated acid complement. These saturated acids have been shown to increase plasma cholesterol concentrations (Bonanome, A., and Grundy, S. M., New Eng. Jour. Med. 318: 1244-1248 (1988)), and trans unsaturated fatty acids have been recently shown to raise low density lipoprotein serum cholesterol levels and to lower high density lipoprotein serum cholesterol levels in adults fed fats having these acids (Mensink, R. P., and Katan, M. B., New Eng. Jour. Med., 323:439-445 (1990)). Moreover, in Western countries, there is a general trend away from high calorie foods for weight control, and decreasing dietary fats has been of special interest since fats have a significantly higher caloric density than either carbohydrates or protein. Hence, a goal of recent research in the food industry has been to minimize or eliminate lauric fats and partially hydrogenated fats in food products, and to decrease caloric intake from fats.
It would be desirable to have low calorie filling fats that contain little or no lauric or trans unsaturated fats. It would also be desirable to have quick-setting, adherent cream fillings that can be used in sandwich biscuit products to minimize misalignment and decapping.